In his first-ever interview, the sole Australian survivor of the Waco siege has revealed to 60 Minutes what really took place during the 51-day stand-off, and why he believes crazed cult leader David Koresh will one day return to Earth as the son of God.

Fighting ISIL the main agenda point for PM's first US visit

Fighting Islamic State and the Trans-Pacific Partnership trade agreement will be key talking points when Prime Minister Malcolm Turnbull meets US President Barack Obama at The White House later this month.

Mr Turnbull will visit Washington for the first time as Prime Minister on January 18 and 19 to discuss regional and global challenges, including combating IS in Iraq and Syria.

The alliance with the United States is fundamental to Australia's national security, the Prime Minister's office has said.

"Our two countries are closely linked in every way - economically, culturally, historically and above all sharing the same values of freedom, democracy and the rule of law - at home and around the world."

The two leaders are also expected to discuss the ratification and implementation of the Trans-Pacific Partnership.

While in the US, Mr Turnbull will address the Center for Strategic and International Studies on national security and will promote Australia as a trade and investment destination to the US Chamber of Commerce.